U.S. Pat. No. 7,762,954, issued on Jul. 27, 2010, is directed to an ultrasonic imaging catheter that is provided with a flexible circuit electrically coupled to a transducer array mounted on the distal end of the catheter, a portion of the flexible circuit being helically wound about the catheter in order to enhance the flexibility of the circuit. The catheter can be a balloon catheter which is also provided with a stent mounted on the balloon, the stent carrying one or more drugs designed to be eluted or washed into a patient's blood stream after the stent has been delivered, by the balloon catheter, into a target area within the patient's vascular system.